Human Cells Flashcards
1
Q
What name is given to the body cells which are not involved in reproduction?
A
Somatic cells
2
Q
By what process do somatic cells divide to produce more somatic cells?
A
Mitosis
3
Q
What name is given to the human cells involved in producing cells for reproduction?
A
Germline cells
4
Q
How many chromosomes are found in germline cells?
A
46
5
Q
By what process do germline cells produce more germline cells?
A
Mitosis
6
Q
In which part of the body are germline cells found?
A
Ovaries and testes
7
Q
By what process do germline cells produce the gametes?
A
Meiosis
8
Q
How many eggs/sperm are produced when a germline cell divides by meiosis?
A
4
9
Q
Name the two types of stem cell
A
Embryonic stem cells and tissue stem cells
10
Q
What word is used to describe the ability of embryonic stem cells to divide into almost any cell type
A
Pluripotent
11
Q
What word is used to describe the ability of tissue stem cells to divide into a limited range of cell types?
A
Multipotent
12
Q
Name 5 uses of stem cells
A
- Model cells to investigate how diseases develop
- Model cells to investigate how drugs work
- Corneal repairs
- Skin grafts
- Bone marrow transplants (in the treatment of leukaemia)
13
Q
What name is given to the abnormal mass of cells formed by uncontrolled cell division of cells?
A
Tumor
14
Q
To which carbon attachment point do bases and phosphates attach in a DNA nucleotide
A
Carbon 1 and carbon 5
15
Q
What name is given to the backbone of a DNA strand from deoxyribose sugar and phosphate?
A
Sugar-phosphate backbone
16
Q
What type of bonds form between bases on two complimentary strands?
A
Hydrogen bonds
17
Q
What term is used to describe the fact that the two strands of DNA run in opposite directions?
A
Antiparallel
18
Q
Name the two ends of one DNA strand
A
3’ and 5’
19
Q
Name given to the short sequence of nucleotides that attach to the 3’ end of the parental strand about to be replicated
A
Primer
20
Q
What name is given to the enzyme needed to replicate the strands during DNA replication?
A
DNA polymerase
21
Q
How is the replication of a leading strand described because it is replicated without any interruptions?
A
Continuous
22
Q
Name the enzyme needed to join the fragments together in the lagging strand?
A
Ligase
23
Q
Name 5 requirements of DNA replication
A
DNA template strand, ATP, DNA nucleotides, Primers and enzymes (DNA polymerase and Ligase)
24
Q
What word is used to describe the fact that you are making multiple copies of a piece of DNA in PCR
A
Amplification
25
Describe the first stage of PCR
Heat the DNA strand to approx 95°C to denature the DNA and break the hydrogen bonds to separate the strand
26
After heating the DNA strand it must be cooled down to 50-65°C - Why?
So that primers can attach to the DNA
27
Lastly the DNA is heated to 70-80 degrees to allow an enzyme to replicate the strand. Name the enzyme involved
Heat-tolerant DNA polymerase
28
Name three uses of amplified DNA produced through PCR
Forensic (crime scene investigation) medical (genetic disorder diagnosis) and paternity disputes
29
Describe 3 differences between DNA and RNA
•Number of strands
•Deoxyribose + ribose sugar
DNA contains thymine RNA contains Uracil
30
In which region of the cell does transcription take place
In the nucleus
31
Where does transcription begin on the DNA strand?
Promoter region
32
Name the region kn the DNA where transcription ends
Terminator
33
What process follows the formation of the primary transcript of mRNA
Splicing
34
Where does the process of splicing occur
Nucleus
35
What process follows the formation of a primary transcript?
Splicing
36
The same piece of DAN can be used to make several proteins due to the fact different regions can act as axons and introns. What is this known as?
Alternative RNA splicing
37
Where does translation occur
In the ribosome
38
Where are tRNA molecules found
In the cytoplasm
39
What name is given to every 3 bases on an RNA
A codon
40
An anticodon acts as a code word to attach someone on the other end of a tRNA molecule - what attaches to this?
An amino acid
41
What bonds form between codons and anticodons?
Hydrogen bonds
42
What bonds form between adjacent amino acids when tRNA anticodons attach to mRNA codons?
Mainly peptide bonds
43
What happens to the tRNA and mRNA at the end of translation?
It detaches from a ribosome and is released back into the cytoplasm for reuse
44
Name some functions of proteins created during protein synthesis?
Enzymes, hormones, antibodies, structural proteins
45
Name 3 single point mutations
Insertions, deletions and substitutions
46
Name two point mutations which cause the frame shift effect
Insertion and deletion
47
Substitution usually usually results in only one amino acid being changed. When could substitution have a major effect on the individual?
If a codon is replaced by a stop codon
48
What name is given to proteins which are still able to function but have had only slight changes made to their structure?
Missense mutations
49
Name the term used to describle proteins which have undergone mutations and cannot function at all
Nonsense
50
What name is given to a mutation where introns are retained in error during splicing
Splice-site mutations
51
Name 4 examples of chromosome mutations
Deletion, duplication, inversion and translocation
52
What name is given to the mutation where some of the Gene's from one chromosome break off and join with the genes on a completely different chromosome?
Translocation
53
What name is given to a mutation when some of the genes rotate 180° on a chromosome?
Inversion
54
What name is given to fusion to the fusion of molecular biology, statistical analysis and computer technology in the study of the human genome
Bioinformatics
55
What name is given to the complete sequencing of a person's DNA bases
Personalised genomic sequencing
56
What name is given to the use of genomic information in choosing pharmaceutical drugs
Pharmacogenetics
57
What are the advantages of pharmacogenetics?
It allows for more effective treatment by selecting a suitable drug and the correct dosage
58
What type of sequences make up the genome
Coding sequences and non-coding sequences
59
What name is given to the thousands of biochemical reactions that occur in living cells
Metabolism
60
The quantity of energy consumed by an organism per unit time is a measure of what rate?
Metabolic rate
61
Name two types of metabolic pathway
Anabolic (build up) and catabolic (breakdown)
62
Metabolic reactions sometimes have places where steps can be bypassed, what are these pathways known as?
Alternative routes
63
Give three properties of a catalyst
* Lowers activation energy
* Increases the reaction rate
* Remains unchanged at the end of the reaction
64
What state is reached when two reactants have bonds broken and they are in a position that is unstable and ready to form a product?
Transition state
65
What substance are enzymes made of?
Protein
66
What name is given to the area on an enzyme that meets with a substrate?
Active site
67
What determines the shape of an active site?
The sequence of amino acids in a poly peptide chain that makes up an enzyme molecule
68
Give the term used to describe the fact that the active site has a strong attraction for the substrate?
High affinity
69
In order for the enzymes active site to fit the substrate more closely, the shape of the active site and enzyme change slightly- what is this called?
Induced fit
70
Fill in the missing phrase: "the shape of the active site determines the ___________ of reactants."
Orientation
71
In an enzyme controlled reaction, the reaction rate will increase as the substrate concentration increases up until a certain point. After that the rate of reaction does not increase, why is this?
All the active sites have been occupied, therefore enzymes become a limiting factor
72
What can be done to increase the rate of an enzyme controlled reaction once all of the active sites on the enzyme are occupied and substrate has already been increased?
Add more of the enzyme to the reaction
73
In a metabolic pathway, metabolite W binds with enzyme 1 to form X, which then binds with enzyme 2 to form Y, which finally binds to enzyme 3 to form metabolite Z at the end of the pathway. If there is a fault in a gene for enzyme 2 which metabolite would build up?
Metabolite X
74
What name is given to a substance that decreases the rate of an enzyme-controlled reaction?
An inhibitor
75
Name three types of inhibitors/inhibition
* Non-competitive and competitive inhibitors
| * Negative feedback inhibition
76
What happens to the rate of reaction in an enzyme-controlled reaction that is affected by a competitive inhibitor?
Decreases the rate of reaction but doesn't stop it altogether because occasionally the substrate will still bind due to competition
77
Where does a non-competitive inhibitor bind to?
An allosteric site (a site away from the active site)
78
What does a non-competitive inhibitor do to the shape of an enzymes active site?
Changes the shape of the active site
79
Why does a reaction affected by a non-competitive inhibitor stop the reaction altogether?
Because the shape of the active site has changed permanently and it no longer recognises the substrate
80
What name is given to the series of metabolic pathways that brings about the release of energy through foodstuff and the regeneration of ATP?
Cellular respiration
81
Name 3 processes in the body that require ATP
Muscle contraction, nerve impulses and protein synthesis
82
Name the three stages of respiration
Glycolysis, Citric acid cycle and Electron transport chain
83
Name the two phases of glycolysis
Energy investment and energy payoff stage
84
Where in the cell does glycolysis take place?
In the cytoplasm
85
How many ATPs are need to be invested in the energy investment phase of glycolysis?
2ATPs (per glucose molecule)
86
How many ATPs are made during the energy payoff phase to give a net gain of 2ATPs?
4ATPs
87
What enzymes remove hydrogen ions and electrons from glucose?
Dehydrogenase enzymes
88
Name the coenzyme molecule that acts as a carrier of the hydrogen ions and electrons
NAD
89
Where are all the hydrogen ions and electrons taken to by the NADH (after it picks up H+)
The electron transport chain
90
What is the final product of glycolysis which passes to the citric acid cycle?
Pyruvate
91
Where does private diffuse into to take part in the citric acid cycle?
The matrix of the mitochondria
92
What does pyruvate combine with to form citrate in the citric acid cycle
Oxaloacetate
93
What has is released during the citric acid cycle
Carbon dioxide
94
What does citrate break down into during the citric acid cycle?
Oxaloacetate
95
What do dehydrogenase enzymes do during the citric acid cycle?
Remove hydrogen ions and electrons
96
Name the carrier that transports the hydrogen ions and electrons to the third stage of respiration
NAD
97
How many ATPs are made during the citric acid cycle
1 ATP
98
What does the electron transport chain consist of
A series of electron receptors
99
What is used to pump hydrogen ions across the inner membrane of the mitochondria?
Electrons
100
What enzyme is used to join ADP and Pi together during the electron transport chain
ATP synthase
101
What is the name of the final electron receptor
Oxygen
102
Whenever hydrogen ions combine with oxygen during the electron transport chain what is formed?
Water
103
Is oxygen needed for the electron transport chain
Yes, because it acts as the final electron acceptor
104
Why is it that at any given time, the body has a fairly constant amount of around 50g. Yet it is constantly being made?
It is broken down just as fast as it is being made
105
During strenuous exercise, what type of respiration does the body carry out?
Lactate metabolism
106
Which of the two stages DO NOT occur because of a lack of oxygen
Critic acid cycle and electron transport chain
107
During lactate metabolism how many ATPs are made
2 ATPs
108
What is pyruvate converted to after glycolysis
Lactate
109
What debt is said to have built up during lactate metabolism
Oxygen debt
110
What substance is reformed following the oxygen debt being repaid?
Pyruvate
111
Which type of muscle fibre is used during endurance events like a long distance run or cycling?
Slow twitch muscle fibres
112
What type of fibre is used during power events such as a sprint or weight lifting
Fast twitch muscle fibres
113
Name the oxygen storing protein present in muscle cells
Myoglobin
114
Which oxygen storing protein has a higher affinity for oxygen between haemoglobin or myoglobin?
Myoglobin
115
Which type of muscle fibre contains many mitochondria, tire slowly, contract over a long period of time and have many blood capillaries & myoglobin?
Slow twitch muscle fibres
116
Which type of muscle fibre contains low numbers of mitochondria, tire easily, contract quickly and have low levels of blood capillaries and myoglobin?
Fast twitch muscle fibres
117
What is the major storage fuel used by fast twitch muscle fibres?
Glycogen
118
What is the major storage fuel used by slow twitch muscle fibres?
Fats?
